1. Field
Embodiments of the present invention pertain to the field of electronic device manufacturing, and in particular, to wafer etching.
2. Description of Related Art
In electronic device manufacturing, electronic devices are formed on a wafer. Typically, layers of various semiconducting, conducting and insulating materials are utilized to form the integrated circuits. These materials may be doped, deposited and etched to form electronic devices.
Decreasing the dimensions of electronic devices and increasing the level of their integration are two of the major trends n the current electronic device manufacturing. As a result of these trends, the density of elements forming a semiconductor device continuously increases. The shrinkage of the semiconductor devices down to submicron dimensions requires that the routine fabrication of their elements also be performed on the submicron level. In addition, to increase the level of the device integration, structures forming electronic devices may be stacked on top of each other.
Typically, an electronic device is fabricated using many layers of films. Each of these layers may be created using a mask that dictates the pattern of the layer. The accuracy of this pattern is extremely critical in manufacturing the chip.
As a line width of a circuit of the electronic device becomes narrower, and a wavelength of a light source for the exposure of the photoresist is shortened, it becomes more difficult to obtain a desired width of the photoresist to form a device feature.
Generally, plasma etching may be used to fabricate integrated circuits. It typically involves a high-speed stream of glow discharge (plasma) of an appropriate gas mixture being shot at wafer. Typically, in plasma etching a vertical etching rate is substantially greater than a lateral etching rate. As a result, reducing the photoresist in lateral dimension to achieve a desired width of the photoresist may not be performed successfully. Furthermore, a line edge roughness (LER) can be generated by a structure of the resist that affects subsequent processes, for example an etching process, and, negatively influences electrical properties of the electronic device.